I know this already (minimally) exists in the editor..when you change lines without saving, the line number becomes bold. But at a quick glance, it's hard to tell which lines have been modified since the last save. If possible, could you add a new highlighting rule under the display tab for "modified lines" foreground and background color?

If you don't understand what I am asking, I would basically like this style line flags, but instead of white background and yellow flag, you can also set your own custom colors:



Thanks!